Practical synthesis of manganese oxide MnO2·0.5H2O for an advanced and applicable lithium ion-sieve

Solid-phase reactions were used for the synthetization of the spinel Li 1.6 Mn 1.6 O 4 powder and the lithium ion-sieve MnO 2 ·0.5H 2 O was subsequently obtained by the leaching of the lithium. The physical characterization showed that the polycrystalline precursor and the MnO 2 ·0.5H 2 O were nearly pure spinel, as well as that during the process of the adsorption-desorption, the structural stability was high. The Langmuir isotherm and pseudo second-order kinetics model showed consistency with the adsorption behavior , which indicated the presence of homogeneous adsorption sites for the lithium adsorption and that its process was chemisorption . Adsorbents were found to remain being characterized with a relatively high Li + uptake (26.13 ​mg ​g −1 ) with low manganese extracted (1.71%) after the circulation experiment was performed up to 5 times, proving a significant repeatability and stability for the lithium ion-sieve. The concentration factors exhibited the highly selective adsorption capacity for absorbent from Qarhan raw brine with high concentrations of Na + , K + , Ca 2+ , Mg 2+ . The adsorbents could be efficiently used for Li + recovery from Salt Lake brine as well as its excellent potential for further application.